Abstract Apparatus and method for removing solids which build up on the cathode of an electrolytic cell, particularly an electrolytic cell used in the treatment of waste water such as sewage or industrial wastes. The cell preferably comprises a metallic hollow tube which may form the cathode, and a lead dioxide-coated anode disposed within, but electrically insulated from, the encircling cathode. The electrolyte flows through the cell in the space between the anode and encircling cathode. In the electrolytic treatment of organic and inorganic waste materials, various chemical deposits, particularly including calcium and magnesium salts of orthophosphate and carbonate as well as calcium and magnesium hydroxide tend to become deposited on the cathode surface and soon prevent proper cell operation. Such deposits are removed periodically by injecting pressurized air into the cell at preselected time intervals. During periods of air injection, a predetermined minimum amount of air is injected dependent upon the rate of liquid flow through the cell.
The method of claim 1 in which the cell is in the form of a hollow metal tube which comprises the cathode and the anode comprises a tubular rod which is centrally positioned relative to said hollow tubular member.
Claim 2
Dependent Claim
38 words
The method of claim 1 in which the rate of air injection in relation to the rate of waste water flow through the cell is at least as great as that represented by curve A of FIG. 3.
Claim 3
Dependent Claim
16 words
The method of claim 3 in which the anode-cathode spacing is about three-sixteenths of an inch.
Claim 4
Dependent Claim
44 words
The method of claim 3 in which the rate of air injection does not exceed a value where the volume of air injected into the cell each minute is more than about 14.5 times the effective volume of the anode-cathode space of the cell.
Claim 5
Dependent Claim
17 words
The method of claim 3 in which the air is injected as a plurality of discrete bursts.
Claim 6
Dependent Claim
16 words
The method of claim 6 in which the bursts of air are provided about 30 minutes.
Claim 7
Dependent Claim
19 words
The method of claim 7 in which each said burst of air has a duration of about 30 seconds.